Word Study
telemarketing
CIDE DICTIONARY
telemarketing, n.
the use of the telephone as an interactive medium for promotion; calling potential customers by telephone for the purpose of selling something; -- applied especially to calls made to persons who have not previously contacted the seller. [WordNet 1.5]
OXFORD DICTIONARY
telemarketing, n. the marketing of goods etc. by means of usu. unsolicited telephone calls.
Derivative
telemarketer n.
For further exploring for "telemarketing" in Webster Dictionary Online